1. Field of the Invention
The present invention relates generally to safety mechanisms and systems for powered land vehicles, and more specifically to a surface engaging system for dissipating the energy of a vehicle collision. The present invention generally comprises a surface friction platform which is automatically or manually lowered from beneath the vehicle to engage the underlying surface and provide frictional resistance. The downward force imparted also lifts the vehicle to at least some extent, thereby imparting additional downward force upon the friction platform.
2. Description of the Related Art
Modern motor vehicles have incorporated ever more sophisticated and numerous safety features (passive restraint systems, or "airbags," antilock braking systems, etc.) as technology has advanced. These features have generally come to be recognized as being critical to our transportation system as ever increasing numbers of vehicles crowd the roadways. A review of insurance statistics and rates indicates clearly that motor vehicle accidents and collisions are increasing, due to the ever more crowded road conditions. While the above noted safety features have provided a reduction in injuries and fatalities, they have done nothing to reduce the impact forces which are imparted to the vehicle(s) at the moment of a collision. Motor vehicles by their nature have relatively low rolling resistance, for efficiency and economy of operation. While modern tires and braking systems are capable of producing relatively high decelerative forces, the assumption here is that the vehicle operator will react to an impending emergency in time to stop the vehicle with such conventional systems.
Unfortunately, this is not always the case, and some form of device for automatically engaging the surface beneath the vehicle in the event of first contact, or perhaps automatically deploying such a surface engaging device according to remotely sensed distance and closing speed parameters, would be of great assistance in further reducing injuries and property damage due to vehicle collisions. Alternative manual deployment of such a device would provide other benefits as well, in reducing auto theft, preventing "rollaway" accidents, and assisting in other situations where it is critical that movement of the vehicle be stopped or prevented.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 3,472,332 issued on Oct. 14, 1969 to Edward M. Halvajian, titled "Combination Impact Cushioning Bumper And Automatic Roadway Brake," describes a linkage between a telescoping bumper and a plate, which causes the forward edge of the plate to drop downwardly and contact the surface underlying the vehicle. Only a relatively narrow transverse edge of the plate contacts the underlying surface, in comparison to the relatively large surface area of the contact plate of the present invention, in which a linkage causes the platform to descend essentially horizontally to contact the underlying surface essentially completely over its entire lower surface area. It is a well known physical principle that frictional forces increase with surface area, even when the total pressure remains the same. The present invention, with its large surface engaging area, provides considerable advantage over the Halvajian device. Moreover, the activation means of the present mechanism provides much more rapid and positive engaging of the device with the underlying surface, than does the Halvajian mechanism.
U.S. Pat. No. 3,495,676 issued on Feb. 17, 1970 to Phillip Graham, titled "Safe Vehicle Body," describes a vehicle in which the collapse of formed structures around the vehicle, cause the release of spring loaded struts which pivot downwardly to engage the underlying surface. Graham notes that the distal ends of the struts may comprise spikes or shoes, but in either case, the surface contact area is considerably smaller than the large platform area provided by the present invention.
U.S. Pat. No. 4,025,098 issued on May 24, 1977 to Tadeusz Powaska, titled "Bumper Assembly For A Motor Vehicle," describes a bumper system incorporating shock absorbing lateral bumpers which shock absorbing actions are independent of one another, and telescoping front and rear bumpers which are interconnected with one another, i.e., an impact compressing the front bumper also causes the rear bumper to retract, and vice versa. Powaska does not disclose any mechanism for engaging the surface beneath the vehicle, either by impact with his bumper system or in any other way, as opposed to the present automated surface engaging system.
U.S. Pat. No. 4,679,838 issued on Jul. 14, 1987 to Stanley J. Mikina, titled "Vehicle Collision Bumper," describes a mechanism wherein a collapsing input on a bumper results in a torsional force being imparted to an elastomer coupling, which produces a restorative force to extend the bumper after impact. A ratchet mechanism is included, with retractile force on the bumper resulting in the rotation of the ratchet wheel holding the elastomer coupling. Mikina does not disclose any form of device for frictionally engaging the surface beneath the vehicle, either due to bumper collapse or otherwise, whereas the present invention includes such undersurface frictional engaging means as one of the main objects of the invention, particularly including means for triggering the deployment of the surface engaging device when one of the contact frames of the vehicle is collapsed, or when other detecting means are used to trigger the deployment of the device.
U.S. Pat. No. 4,786,459 issued on Nov. 22, 1988 to James D. Mundo, titled "Vehicle Impact Energy Absorber," describes a helically threaded post supporting the bumper and engaging a mating threaded sleeve. The sleeve is frictionally held within the bumper. When an impact occurs, the sleeve is forced along the threaded post, and its rotation is restricted by the frictional clutch means holding it in place in the bumper. However, Mundo does not provide any means for engaging the surface beneath the vehicle, nor any means for his bumper mechanism to trigger the deployment of such a surface engaging friction platform, which platform and deployment means are a part of the present invention. U.S. Pat. No. 5,226,685 issued on Jul. 13, 1993 to Yung-Hsing Chen, titled "Collision-Avoidance Safety Apparatus For A Car," describes a generally U-shaped bar which may be pivotally mounted between its arms at each end of a car or other motor vehicle. The crossmember of the U extends outwardly from the bumper, with the arms extending somewhat downwardly beneath the vehicle structure. When an impact occurs, a force vector deflects the upwardly oriented crossmember further upward, thus causing the arms to swing downwardly and contact the underlying surface. However, the Chen system teaches away from the present invention, in that Chen provides wheels at the ends of the downwardly swinging arms, rather than braking means. Thus, a vehicle equipped with the Chen device would have no means of stopping in the event of brake malfunction, either as a result of a collision or due to mechanical failure. The present invention provides a positive braking system.
U.S. Pat. No. 5,257,842 issued on Nov. 2, 1993 to Stanley A. Sherno, titled "Collision Impact Absorber," describes a device much like that of the '685 U.S. patent to Chen, discussed immediately above. The Sherno device differs in that it is pivotally mounted to the vehicle structure behind the bumper, and extends forwardly and downwardly outside the bumper. An impact produces a downward force component on the lowered outer end, which translates to an upward force component to the vehicle. This lifts the impacted end of the vehicle. However, the Sherno mechanism does not provide any means of engaging the underlying surface of the vehicle with his device, and thus cannot provide any braking action, as is provided by the present invention.
British Patent Publication No. 361,337 accepted on Nov. 18, 1931 to Aladin A. Silva, titled "Improvements In Automatically Operated Brakes For Vehicles," describes a system of three shoes or drags which drop from beneath the vehicle when triggered by a bumper impact. The bumper is mounted on arms which are in turn pivotally attached to a crossmember extending between the two front leaf spring suspension attachment points. The Silva bumper thus must pivot downwardly to release the drags, rather than moving rearwardly to trigger the actuation of the braking means, as in the present safety device. Moreover, the pivotally mounted drags of the Silva device differ from the friction platform(s) of the present invention, in that the present platform(s) provide a considerably larger surface contact area and remain parallel to the underlying surface at all times for increased braking efficiency.
British Patent Publication No. 592,295 accepted on Sep. 12, 1947 to Arthur J. Davies, titled "An Automatic Brake And Stop, For Motor Vehicles," describes a mechanical system which is activated either by bumper contact with another object, or by activation of a lever inside the vehicle. Movement of the lever (either by means of rearward movement of the front bumper which is connected to the lever, or by the vehicle operator) triggers the release of a pair of rearwardly pivotally mounted arms or struts, the forward ends of which fall from beneath the vehicle to jam against the pavement and which cause the front of the vehicle to lift due to the forward motion of the vehicle. Thus, the system of the Davies '295 British Patent Publication is more closely related to the system disclosed in the Graham '676 U.S. patent discussed further above, than to the present invention with the large area of its surface engaging friction platform.
Canadian Patent No. 868,748 issued on Apr. 20, 1971 to Franklin Goggins, titled "Antiskid Apparatus For A Vehicle," describes various embodiments of auxiliary wheels, casters, rollers, and/or skate blades which are normally retracted, but which may be selectively extended to provide supplemental braking, steering, or other effects as desired. The two most notable distinctions between the Goggins systems and the present invention are (1) Goggins provides supplementary low friction means (wheels, etc.), while the present invention is directed only to a supplementary friction brake; and (2) the Goggins systems require manual activation, whereas the present system may be automated.
Finally, Japanese Patent Publication No. 57-95233 published on Jun. 14, 1982 to Riyouji Munetou describes (according to the English abstract) a rear wheel chocking system, triggered by frontal impact and rearward movement of the front bumper. When the bumper moves rearwardly upon impact, it actuates a linkage to cause the chocks to drop downwardly in front of the rear wheels. The system is automated, as is the present system, but relies only upon stopping rotation of the rear wheels by chocking them. In contrast, the present invention provides one or more surface engaging friction platforms of larger area, which automatically drop to engage the underlying surface below the vehicle. The present system does not affect the conventional vehicle wheels or tires in any way, as does the device of the Japanese publication.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.